Draft regulator



3 G. DONOVAN ET AL 7 1,978,488

DRAFT REGULATOR Filed Nov. 1, 1933 vn a rokS 25- Patented Oct. 30, 1934 i911 .UNITED STATES PATENT OFFICE ,1

A inmate-L" I fi Fi R GUi RY a. George Lucas Donovan and williamlirthur Fox,

Vancouver, British Columbia, Canada 1 November 1, 1933,

In Canada December 19,1932

1 Claim. (Cl. 236-93) The invention relates to improvements in mais to have a hole cut in it large enough but not chines or devices for regulating stack velocity too large to be properly covered by collar of castor draft in smokepipes, fiues, chimneys or stacks; ing 1. Casting 1 is attached closely and firmly and the objects of our invention are to accomto Smokestack by screws or bolts through holes plish this end automatically, with a simply conin collar of casting and through holes bored in my structed and strongly built self-contained masmokestack in similar relative positions. chine or device, simply and easily installed, with Assuming that machine or device is properly infew p d W c may be r adi y accessible stalled and movable quadrant shaped portal 2 is for inspection or repair, and generally to adapt in closed position, notch in side of quadrant itself to better perform the functions required against stop peg 3, as soon as stack begins to 5 of it. heat up said quadrant shaped portal 2 will im- We attain these objects by the mechanism 11- mediately commence to open and may continue lustrated in the accompanying drawing, in to open until other notch in adjoining quadrant whichcomes against stop peg 3 in casting 1. When Fig. 1 shows a front view of the device with in this position automatic draft regulating ma- 70;

detail omitted. chine or device is wide open, allowing the cooler Fig. 2 is a plan view of the detail omitted air to be drawn through the opening and up the from Fig. 1. chimney instead of the heat from the fire or Fig. 3 is another view of single main casting furnace etc. Again as the stack cools off the as shown in Fig. 2, but without other parts. movable quadrant shaped portal 2 closes up the 75 Fig. 4 shows front view of revolving quadrant opening automatically, in similar manner. shaped portal. This operation takes place as follows, heat in- Fig. 5 shows side view of quadrant shaped side smokestack causes bimetal coil 6 to twist, portal as shown in Fig. 4. turning shaft 5 on other end of which is movable Fig. 6 shows front view of concave spring. quadrant shaped portal 2, which can be revolved so Fig. 7 shows washer. to point where it comes against stop peg 3 in cast- Fig. 8 shows side view of bimetal thermostatic ing 1. At this point draft regulator is wide open coil. and quadrant shaped portal 2 cannot move fur- Fig. 9 shows shaft with split pin. ther in that direction. The bimetal coil 6 how- Similar letters refer to similar parts throughever may continue to keep on twisting and turn- 85. out the several views. ing shaft 5 with split pin 10 and nuts '7 and 8. Referring to the drawing: And if so then concave spring 4 becomes a slip- 1 represents the main casting to which is atping or frictional clutch against collar or shoulder tached one end of bimetal coil 6 through hole on shaft 5, thus saving the bimetal coil 6 from in coil by screw 12. Through hole in other end injury or damage caused by undue strain because 90 of bimetal coil 6 is split pin 11, which holds that there is none.

end of bimetal coil from slipping sideways out of As soon as stack begins to cool off, quadrant slot or fork in shaft 5. End of bimetal coil 6 shaped portal 2 begins to close, and continues to which is th ou S t fork in Shaft 5 having close, turning in the opposite direction from when free r Om t0 Sli back and forth along Slot opening, until when stack is cold and then will 95 fork in Shaft which passes thlfough hole 13 in be completely closed. Frictional clutch again shank of castmg 1 Washer 9 bemg held against going into action after notch in quadrant shaped the shank of casting 1 by split pin 10. Shaft 5 o t 12 r 1 Which goes through hole 13 in shank of casting 1 g g egums to ongmal 0 Used posmon agam-st extends through hole in concave spring 4 which 0 hole in spring is only large enough to allow spring The actlon opening and closmg of automatlc to go no further than the collar or shoulder at draft regulajtmg deYlce depetlds on the amount end of screw thread near end' of shaft 5 concave of heat passmg by blmeta'l 6 and escapmg up side of concave Spring 4 is turned away from the chimney, and where a constant heat is delivcasting 1 but next to quadrant'shaped portal 2 ered into a firebox regardless of draft conditions 105 Shaft 5 goes through hole in centre of quadrant Such as by an Oil burner this type of draft sushaped portal 2 which is held a ain t th four lator is especially effective in holding back the outside ends of concave spring 4 by adjusting h m going p the m y as h v ry nut 7 which is held in position by locknut 8. heat going up the chimney regulates it. Another For operation of machine or device, Smokestack feature of the machine is that if pushed out of 1 0 connected to a smoke pipe or fiue, a circular projection on said casting having a flat end surface, a coaxial bearing shank formed on said flat sur face and projecting inwardly towards thepipe or flue, a central bore in said shzm'khaving a shaft rotatably mounted therein, a bimetallic coil surrounding said shank and extending intov the pipe or flue, said coil having one end connected to the shank and the other end connected to the shaft, a circular plate mounted on or at the end of said shaft in close engagement with the flat surface, a frictional clutch connection between said shaft and plate whereby said plate will be rotated on rotation of said shaft by the bimetallic coil, a stopon said flat surface to limit the rotation of the plate in both directions, openings in said plate and fiat surface, said openings being arranged to register when the plate is rotated in one direction and to be out of register when the plate is rotated in the opposite direction, substantially :as set forth..

GEORGE LUCAS DONOVAN. WILLIAM ARTHUR FOX. 

